Optical lenses are typically made of various materials, such as polycarbonates and high index plastics, as well as those materials currently marketed under the trade names CR39® and TRIVEX™ (both readily commercially available from PPG Industries, Pittsburgh, Pa.).
In order to finish and make these lenses ready for fitting into a lens frame, it is necessary to edge the outer periphery of the lens, to give it the proper cross-section to fit in an eyeglass lens frame. Typically, this is done by an edging machine, which includes a rough-cut wheel for cutting out the shape, fine grinding and finishing wheels for further shaping of the lens, and polishing and beveling wheels for providing the final contour.
Depending on the lens material, the grinding operation creates abrasive swarf material that requires removal in order for proper use of any type of abrasive device. Typically, the wheels have buildup of swarf during the operation, which imparts itself onto the lens or, alternatively, the grinding process does not remove the excess material. This creates the need to manually remove the swarf from the lens. Any swarf that is not readily removed during the grinding of the edging operation, interferes with the operation and, at the very least, slows it down and may add to several hand finishing steps necessary at the end, or an improper lens configuration.
TRIVEX™ has been a particularly troublesome material to shape and finish. However, TRIVEX™ does appear to be a new and preferred lens making material. Unfortunately, conventional forming wheels have resulted in much scrap and have otherwise been proved to be unsuitable for use with TRIVEX™ materials for lenses. Therefore, it has become a goal to provide an abrasive wheel capable of processing TRIVEX™ lenses that can also be used for all other type of lens materials.
In the optical industry today, the “one-hour” optical labs and the like have made it necessary for increased efficiencies in the processing of optical lens production. Therefore, it is desired to eliminate swarf removal on the optical lens by hand, regardless of the material used, which is labor intensive and time consuming.
Therefore, it is a goal in the art to provide rough-cut, fine grinding, finishing, polishing and/or beveling wheels, and methods for using the same, that eliminate the need for manual swarf removal.